1. Field of the Invention
The present invention relates to an apparatus and method for stretching a continuously moving elastomeric web in a cross machine direction. The invention particularly concerns an apparatus and method for stretching a continuously moving elastomeric material in a cross machine direction and bonding the material to at least one facing sheet thereby providing a stretch-bonded laminate material which is stretchable in the cross machine direction.
2. Description of the Related Art
Absorbent articles, such as disposable infant diapers, feminine care products, incontinence garments and the like, have included stretch-bonded laminate materials. For example, particular absorbent article designs have used stretch-bonded laminate materials for their leg and waist elastics.
Several different conventional methods exist for stretching elastomeric materials in the cross machine direction. Some conventional methods utilize a pair of canted wheels to stretch the elastomeric material in the cross machine direction. For example, U.S. Pat. No. 5,043,036 to Swenson describes an apparatus for stretching an elastomeric material in the cross machine direction which includes two circular pulleys which are canted about their axes. Other conventional methods for stretching elastomeric materials in the cross machine direction utilize a series of gripping devices which are arranged to successively grip and stretch the elastomeric material in the cross machine direction.
Conventional apparatus and methods for stretching an elastomeric material in the cross machine direction, such as those described above, have not been sufficiently satisfactory. For example, the devices may be overly complex and expensive and may not be capable of continuous operation at high speeds. The conventional devices also may not have the capability to provide the web paths which are necessary to laminate facing sheets to the stretched elastomeric web to provide stretch-bonded laminate materials. For example, the conventional devices may be useful in applying individual components, such as waist elastics, to an absorbent article but may not be useful in a laminating process. In addition, many of the conventional apparatus utilize mechanical gripping means or pins which may negatively affect the side edges of the stretched elastomeric material.